Push button switch



Dec. 27, H, F, S N 3,294,942

PUSH BUTTON SWITCH Filed Aug. 10, 1964 v IN VEN TOR.

HOWARD F MA 50M 5 Y /-//5 A TTOEA/EYS United States Patent Ofifice 3,294,942 Patented Dec. 27, 1966 3,294,942 PUSH BUTTON SWITCH Howard F. Mason, Los Angeles, Calif., assignor to The Ansul Company, Marinette, Wis., a corporation of Wisconsin Filed Aug. 10, 1964, Ser. No. 388,353 Claims. (Cl. 200-159) This invention relates to electrical switches and, in particular, to sliding or reciprocating switches which are particularly adapted for utilization as manually operated push button switches.

It is an object of the invention to provide a small, compact, inexpensive, durable and reliable electrical switch. A further object is to provide a push button or manually actuated switch having such characteristics.

It is an object of the invention to provide such a switch which may be used for making circuits or for breaking circuits or for both making and breaking circuits.

It is an object of the invention to provide such a switch incorporating a cam action which provides fast break and fast make operation and which also provides a detect action while permitting overtravel of the switch plunger without damage to the switch elements.

It is an object of the invention .to provide an electrical switch incorporating a housing, a plunger slidably mounted in the housing and movable between first and second positions and having a cam movable therewith, a conductor carried in the plunger and having a pair of exposed contact faces, and a pair of contact carriers mounted in the housing with each carrier including a contact resiliently urged toward the plunger and a cam surface engageable with the cam when the plunger moves intermediate the first and second positions for moving the contacts away from the plunger, with the contacts engaging the contact faces and completing a circuit between the carriers when the plunger is in one of the positions.

It is a further object to provide such a switch incorporating means for manual movement of the plunger from one position to the other and a switch incorporating spring means for urging the plunger to one of the positions. A particular object is to provide such a switch utilizing more than one conductor in the plunger and more than one set of contact carriers permitting control of more than one circuit with a single switch movement. A particular object is to provide such a switch in which the housing is a simple tubular structure with the contact carriers mounted in one end thereof and with the plunger slidably carried in the opposite end.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. The drawing merely shows and the description merely describes a preferred embodiment of the present invention which is given by way of illustration or example.

In the drawing:

FIG. 1 is a side view of a preferred form of the switch; 2

FIG. 2 is an enlarged sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a partial sectional view taken along the line 4-4 of FIG. 2;

FIG, 5 is an exploded view showing the assembly of the switch of FIG. 2;

FIG. 6 is a partial sectional view corresponding to that of FIG. 2 showing the switch with the plunger depressed; and

FIG. 7 is a view similar to that of FIG. 6 illustrating the movement of the contact during switch operation.

The switch includes a housing 10 and a plunger 11 both preferably made of electrical insulating material. In the preferred form illustrated herein, the housing is tubular having a passage 12 therethrough. The plunger 11 carries a peripheral shoulder 13 which engages a mating shoulder 14 of the housing for limiting movement of the plunger in one direction. A guide pin 15 is carried in and projects from the inner end of the plunger 11 and slides in a passage of a plug fitted in .a ring 21 in the other end of the housing 10. The plug and ring preferably are made of electrical insulating material and support contact carriers in a manner to be described below.

A conductor 22, typically a cylindrical slug of copper or silver, is mounted in the plunger 11. The ends of the conductor 22 are exposed at slots 23, 24 provided in the plunger. Another conductor 25 is similarly mounted in the plunger 11 spaced from the conductor 22 and at a different orientation, typically at 90 to the conductor 22. The ends of the conductor 25 are exposed at slots 26, 27 formed in the plunger 11.

A contact carrier 30 having an electrical contact 31 at the upper end thereof and an opening 32 at the lower end for connection of a wire is mounted between the plug 20 and ring 21. The ring 21 may have a tapered opening 33 which converges away from the housing, with the plug 20 having a corresponding tapered form for a push fit into the ring. Slots 34 are provided in the periphery of the plug for receiving contact carriers, with a contact carrier having a slot 35 for engaging a boss 36 of the plug for fixing the carrier relative to the plug. Three additional carriers 40, 41, 42 are provided identical to the carrier 30.

The contact carriers are made of an electrical conducting resilient material and are installed so as to urge the contacts into engagement with the plunger when in the normal positions as shown in FIGS. 2 and 6. Each carrier is provided with a cam surface which may be produced by forming a convex section 45 in the strip of metal comprising the carrier. An annular shoulder 46 on the plunger serves as a cam for engaging the cam surfaces of the carriers as the plunger moves between the positions of FIGS. 2 and 6. In the embodiment illustrated herein, a spring 48 is positioned around the guide pin 15 and engages the plunger 11 and plug 20 for urging the plunger to the upward position of FIG. 2. The plunger may be moved downward to the position of FIG. 6 by manual pressure or by various mechanical or electrical actuating devices. A pin 49 serves to hold the switch together after it has been assembled.

When the switch is in the position of FIG. 2, the contacts of the carriers 30 and 41 engage the faces of the conductor 25, providing an electrical circuit between the two carriers. At this time, the contacts of the carriers and 42 rest on the insulating material of the plunger, resulting in an open circuit between the carriers 40, 42. When the plunger is moved downward, the cam 46 engages the cam surfaces of the carriers, moving all four contacts radially outward from the plunger. When the plunger has moved downward to the position of FIG. 6, the cam 46 has moved past the highest portion of the cam surfaces, permitting the contacts of the carriers to move radially inward and engage the plunger. At this time, the contacts of the carriers 40 and 42 engage the exposed faces of the conductor 22, providing a closed circuit between the carriers 40, 42. The contacts of the carriers 30, 41 now rest on insulating material and provide an open circiut between the carriers 30 and 41. The motion of a contact relative to the plunger is indicated by the line 52 of FIG. 7.

Similar operation occurs when the plunger is moved upward from the position of FIG. 6 to the position of FIG. 2. The cooperation of the cam of the plunger and 13 the'carn surfaces of the carriers provides a fast break and fast make action for the contacts. The cam and cam surface operation also provides a detenting action tending to locate the plunger either in the position of FIG. 2 or of FIG. 6. When the switch is used as a manual push button, this detenting action can be felt by the operator, giving an indication of the switch position. The particular cam and cam surface arrangement utilized also permits overdriving of the plunger without damaging the camming structure.

' While the switch illustrated herein provides for both breaking of one circuit and making of another circuit, the switch of the invention could be produced only for making a circuit or only for breaking a circuit by utilization of only one of the conductors 22, 25 and the corresponding pair of contact carriers. In another alternative arrangement, the spring 48 could be omitted and the switch could be moved from one position to the other in either driection by a positive driving'force which may be manual or powered as desired.

Although exemplary embodiments of the invention have been disclosed and discussed, it will be understood that other applications of the invention are possible and a pairof contact carriers mounted in said housing each including a contact resiliently urged toward said plunger andeach including a cam surface separate from the contact and engageable with said insulating cam when said plunger is intermediate said first and second positions for moving said contacts away from said plunger and maintaining an open circuit between said carriers, with said contacts engaging said contact faces and completing a circuit between said carriers when said plunger is in one of said positions.

2. In an electrical switch, the combination of:

a housing;

a plunger slidablymounted in said housing and movable between first and second positions and having a cam movable. therewith; V

a first conductor carried in saidplunger and having a pair of exposed contact faces;

a second conductor carrier in said plunger and having a pair of exposed contact faces; and

first and second pairs of contact carriersmounted in said housing, each carrier including a contact resiliently urged toward said plunger and each including a cam surface engageable with said cam when said plunger is intermediate said first andsecond positions for moving said contacts away from said plunger, with the contacts of said first pair engaging the contact faces of said first conductor and completing a circuit between said first pair of carriers when said plunger is in said first position, and with said contacts of said second pair engaging said contact faces of said second conductor and completing a circuit between said second pair of carriers when said plunger is in said second position.

3. A switch as defined in claim 2 including spring means engaging said housing and plunger for urging said plunger toward said first position, said plunger including means for manual movement to said second position.

4. In an electrical switch, the combination of:

a housing;

a plunger of insulating material slidably mounted in said housing and movable between first and second positions and having a cam of electrical insulating material movable therewith;

an elongate conductor carried in said plunger disposed normal to the axis of movement of said plunger and having a pair of opposed exposed contact faces; and

a pair of opposed contact carriers mounted in said housing each including a contact resiliently urged into engagement with said plunger and each including a cam surface separate from the contact and engageable with said insulating cam when said plunger is intermediate said first and second positions for moving said contacts radially away from said plunger and maintaining an open circuit between said carriers, with said contacts engaging said contact faces and completing a circuit between said carriers when said plunger is in one of said positions and engaging said plunger providing an open circuit between said carriers when said plunger is in the other of said positions.

5. In an electrical switch, the combination of:

a tubular housing;

a plunger slidably mounted at one end of said housing and movable between first and second positions and having a cam movable therewith;

a conductor carried in said plunger and having a pair of exposed contact faces;

a retainer ring mounted in the other end of said housing and having a tapered passage converging away from said housing;

a mating plug positioned within the passage of said ring and having carrier receiving slots with bosses projecting therein; and

' a pair of contact carirers each disposed in a plug slot and having a slot for receiving the plug boss for fixing the carrier between the ring and plug, each carrier including a contact resiliently urged toward said plunger and each including a cam surface engageable with said cam when said plunger is intermediate said first and second positions for moving said contacts away from said plunger, with said contacts engaging said contact faces and completing a circuit between said carriers when said plunger is in one of said positions.

References Cited by the Examiner UNITED STATES PATENTS 1/1916 Wilcox et al. 200l53 6/1962 Long et al. 200159 

1. IN AN ELECTRICAL SWITCH, THE COMBINATION OF: A HOUSING; A PLUNGER SLIDABLY MOUNTED IN SAID HOUSING AND MOVABLE BETWEEN FIRST AND SECOND POSITIONS AND HAVING A CAM OF ELECTRICAL INSULATING MATERIAL MOVABLE THEREWITH; A CONDUCTOR CARRIED IN SAID PLUNGER AND HAVING A PAIR OF EXPOSED CONTACT FACES; AND A PAIR OF CONTACT CARRIERS MOUNTED IN SAID HOUSING EACH INCLUDING A CONTACT RESILIENTLY URGED TOWARD SAID PLUNGER AND EACH INCLUDING A CAM SURFACE SEPARATE FROM THE CONTACT AND ENGAGEABLE WITH SAID INSULATING CAM WHEN SAID PLUNGER IS INTERMEDIATE SAID FIRST AND SECOND POSITIONS FOR MOVING SAID CONTACTS AWAY FROM SAID PLUNGER AND MAINTAINING AN OPEN CIRCUIT BETWEEN SAID CARRIERS, WITH SAID CONTACTS ENGAGING SAID CONTACT FACES AND COMPLETING A CIRCUIT BETWEEN SAID CARRIERS WHEN SAID PLUNGER IS IN ONE OF SAID POSITIONS. 